Top-secret Cruise missile information ended up in a second-hand shop after a Royal Navy rating sold Ministry of Defence computers to fund his gambling habit, a court martial was told. The thefts came to light only when senior American officials visited the Cruise Missile Support Agency, at Northwood military headquarters, Middlesex, concerned that a submarine exercise had not been properly supported by computer software. Crookes worked at Northwood military headquarters Chief Petty Officer Paul Crookes, a weapons engineer, was interrogated and confessed to selling agency computers and other equipment to pay off his casino debts. Among the items were three laptops which contained sensitive files marked "Top Secret - for UK/USA eyes only". Crookes had sold them for cash at a second-hand store called Computer Exchange. Although he had attempted to adapt the hard drives, they still contained large passages of highly classified information, Lt-Cdr Alison Towler, prosecuting, told the hearing in Portsmouth. Although two of the laptops were still in his possession, investigators recovered the third from the shelves of the shop. "The potential to create a substantial security breach was considerable," said Cdr Towler. The hearing was told that Crookes, who is in his late twenties, was an inveterate gambler who carried on visiting casinos in the "insane" hope that he would one day emerge as a big winner. He had debts of more than Â£120,000. He pleaded guilty to 24 charges of theft and one of attempted theft, and asked for 12 similar offences to be taken into consideration. He had stolen equipment worth Â£16,000 from the agency, where he had a trusted position maintaining computer equipment. Crookes, who had previously been regarded as a candidate for promotion, had also stolen Â£230 from the agency coffee fund. Three naval officers provided reports on his previous good character and excellent work as a weapons engineering artificer. Charles Holt said in mitigation, that Crookes had gambled since he was a child and had sought help from Gamblers Anonymous and had received counselling. He was "thoroughly ashamed" at what he had done. Crookes was dismissed from the Navy, sentenced to a year in military custody, demoted to petty officer and stripped of three good conduct badges. Judge Advocate Timothy Thorne said Crookes had committed offences with a high degree of sophistication for personal gain. He was responsible for a "gross breach of trust" which would have a "corrosive effect" on the Navy and on public confidence in the service, he said. The hearing was told that lax security allowed Crookes to abuse his trusted position at the missile support agency. The job involved installing computers and fault-finding when systems broke down. He was authorised to send computers for repair, transfer old or unserviceable items to stores and order new equipment. Gate guards at Northwood did not always ask to see his written authorisation to remove the equipment because he was a familiar face and was usually waved through without checks, the court martial was told. Crookes had access to MoD funds to acquire new equipment in a hurry and the account allowed him to buy items on credit. A Navy spokesman said that security had been tightened as a result of the case. "Classified material was present in three computers which were stolen. The computers were recovered before being sold on. A security review was conducted and additional measures were put in place."